Sensor

ABSTRACT

A sensor includes a first substrate on a back side of a display panel, a first coil extending in a first direction at a predetermined angle between 0 and 90 degrees with respect to a long-side direction of the first substrate and including a first long-side portion provided with first and second end portions, a second coil including a second long-side portion extending in a second direction, a first leader line including a first end and a second end, wherein the first end is connected to the first end portion, and the second end is connected to wiring on a second substrate arranged to extend at a right angle toward the outside of the sensor from one side of the first substrate, and a second leader line including first end connected to the end portion and a second end connected to the wiring on the second substrate.

TECHNICAL FIELD

The present disclosure relates to a sensor, and particularly, to asensor stacked in a display apparatus and used.

BACKGROUND ART

There is a known position detection apparatus in which a sensor detectsan alternating magnetic field transmitted from a position indicator todetect the position of the position indicator. Examples of knownspecific systems of this type of position detection apparatus include anelectromagnetic (EM) system in which a battery needs to be provided onthe position indicator and an electromagnetic resonance (EMR)(registered trademark) system of using an electromagnetic wavetransmitted by the position detection apparatus through the sensor togenerate power in the position indicator. While the electromagnetic waveis transmitted only from the position indicator to the positiondetection apparatus in the EM system, the electromagnetic wave istransferred in both directions in the EMR (registered trademark) system.

The sensor of the position detection apparatus includes a set of aplurality of first coils (loop electrodes) elongated and extended in afirst direction and second coils (loop electrodes) elongated andextended in a second direction crossing the first direction. Althoughthe first and second directions are usually a long-side direction and ashort-side direction of a rectangle detection region, respectively,Patent Document 1 discloses a technique of diagonally forming the coilswith respect to the long-side direction of the detection region.

In addition, the position detection apparatus requires a controller. Aleader line for connecting the controller and each coil isconventionally arranged outside of the detection region as alsodescribed in Patent Document 1, and the controller is connected to thecorresponding coil on an edge portion of the detection region.Therefore, an invalid area in which the position of the positionindicator cannot be detected is formed outside of the detection region.However, the trend of narrowing the bezel of the display apparatus inrecent years often does not permit to provide a wide invalid area, andreduction of the invalid area is demanded.

With regard to the problem, Patent Document 2 discloses a technique, inwhich the connection point of the leader line and each coil is providedon a center portion of the detection region instead of the edge portion,and the leader lines are arranged between the coils. According to thetechnique, the invalid area provided outside of the detection region canbe minimized.

PRIOR ART DOCUMENT Patent Documents

Patent Document 1: Japanese Patent No. 4648860

Patent Document 2: Japanese Patent No. 4405247

SUMMARY Technical Problems

Incidentally, the position detection apparatus and the display apparatusare placed on top of each other in a tablet terminal, and the displayapparatus usually includes a gate line extended in the long-sidedirection of the detection region. Therefore, when the gate line of thedisplay apparatus is driven by a predetermined signal, the coilsextending in the long-side direction of the detection region areaffected by the signal throughout the entire length. As a result, themagnetic flux generated by the coils affects the operation of thedisplay apparatus, and the user may perceive this as moire patterns.According to the technique of Patent Document 1, all of the coils of theposition detection apparatus are not parallel to the gate line of thedisplay apparatus, and this can reduce the influence on the operation ofthe display apparatus caused by the magnetic flux generated by thecoils.

Therefore, the inventor of the present application is examining toprovide the connection point of the leader line and each coil on thecenter portion of the detection region instead of the edge portion as inPatent Document 2 in the configuration of Patent Document 1 in whicheach coil is formed diagonally with respect to the long-side directionof the detection region in order to reduce the influence on theoperation of the display apparatus caused by the magnetic flux generatedby the coils of the position detection apparatus and in order tominimize the invalid area provided outside of the detection region.However, it has been discovered that if the configuration is adopted,the visibility of the display apparatus is reduced, and the arrangementefficiency of various circuits provided in the tablet terminal isreduced. Hereinafter, the problems will be described in detail.

The tablet terminal generally includes a display module and a circuitunit arranged on the back surface of the display module (surface on theopposite side of the display surface). A display panel of the displayapparatus and a sensor provided with the coils of the position detectionapparatus are arranged in the display module. Various circuits, such asa processor of the tablet terminal, a controller of the positiondetection apparatus, and a control circuit of the display apparatus, arearranged in the circuit unit.

First, the reduction in the visibility of the display apparatus will bedescribed. In the configuration of Patent Document 1, the sensor isarranged on the display surface side of the display panel. In thearrangement, if the connection point of the leader line and the coil isprovided on the center portion of the detection region instead of theedge portion as in Patent Document 2, the leader line also needs to bearranged on the center portion of the detection region, and thevisibility of the display apparatus is reduced.

Next, the reduction in the arrangement efficiency of various circuitswill be described. A rectangle flexible substrate is used to connect thecontroller of the position detection apparatus and the leader line inthe sensor. The flexible substrate is bent and arranged so as to enfoldone side of the sensor. The flexible substrate is connected to theleader line of the sensor in the display module and connected to thecontroller on the back surface of the display module.

A terminal group connected to the leader lines is arranged on an endportion on the leader line side of the flexible substrate. Here, if theleader lines are arranged between the coils as in Patent Document 2, theleader lines are also diagonally arranged when the coils are diagonallyarranged as in Patent Document 1. Therefore, the terminal groupconnected to the leader lines also needs to be diagonally arranged, andthe entire flexible substrate is diagonally arranged. As a result, thecontroller also needs to be diagonally arranged.

FIG. 19 is a diagram illustrating a state in which the flexiblesubstrate and the controller are diagonally arranged. FIG. 19illustrates: a back surface of a display module 100 in which a sensornot illustrated is arranged inside; a controller 102 that provides theposition detection apparatus along with the sensor; and a flexiblesubstrate 101 that connects the sensor and the controller 102. Inaddition, a region A illustrated in FIG. 19 represents a region in whichother circuits in the circuit unit can be arranged. As can be understoodfrom the shape of the region A, if the flexible substrate 101 and thecontroller 102 are diagonally arranged with respect to the back surfaceof the display module 100, there is a region around them in which othercircuits cannot be arranged, and this reduces the arrangement efficiencyof various circuits. Note that if the flexible substrate 101 is formedin a special shape (for example, parallelogram) in the example of FIG.19, the controller 102 can be provided parallel to the back surface ofthe display module 100. However, it is difficult to process the flexiblesubstrate 101 into a special shape, and the crimping operation alsobecomes difficult. In addition, the length of wiring on the flexiblesubstrate 101 becomes nonuniform, and the design of the correctionprocess (S2 in FIG. 9) described later may also become difficult.

Therefore, an object of the present disclosure is to provide a sensorthat can suppress reduction in visibility of a display apparatus andreduction in arrangement efficiency of various circuits even when eachcoil is formed diagonally with respect to a long-side direction of adetection region, and a connection point of a leader line and the coilis provided on a center portion of a detection region instead of an edgeportion.

Technical Solution

A first aspect of the present disclosure provides a sensor including: afirst substrate which, in operation, is arranged on a back side of adisplay panel; a first coil extending in a first direction at apredetermined angle larger than 0 degrees and smaller than 90 degreeswith respect to a long-side direction of the first substrate, the firstcoil including a first long-side portion provided with a first endportion and a second end portion; a second coil including a secondlong-side portion extending in a second direction crossing the firstdirection; a first leader line including a first end and a second end,wherein the first end is connected to the first end portion of the firstcoil, and the second end is connected to wiring on a second substratearranged to extend at a right angle toward an outside of the sensor fromone side of the first substrate; and a second leader line including afirst end connected to the second end portion of the first coil and asecond end connected to the wiring on the second substrate.

A second aspect of the present disclosure provides the sensor accordingto the first aspect, in which a terminal group arranged side by side inthe long-side direction of the first substrate is formed on the secondsubstrate, and the second end of the first leader line and the secondend of the second leader line are connected to the wiring on the secondsubstrate through the terminal group.

A third aspect of the present disclosure provides the sensor accordingto the first aspect, in which the first substrate is a multilayersubstrate including a plurality of layers including a first layer, asecond layer, and a third layer, the first long-side portion is providedin the second layer, the second long-side portion is provided in thethird layer, and the first and second leader lines are provided in thefirst layer.

A fourth aspect of the present disclosure provides the sensor accordingto the first aspect, in which the first and second coils are formed suchthat at least part of a short-side portion of the first coil and atleast part of a short-side portion of the second coil overlap while thesensor is viewed in plan view.

A fifth aspect of the present disclosure provides the sensor accordingto the fourth aspect, in which the first and second coils are formedsuch that an acute angle portion of the first coil and an obtuse angleportion of the second coil overlap while the sensor is viewed in planview.

A sixth aspect of the present disclosure provides the sensor accordingto the second aspect, in which each of the first and second leader linesis provided on a detection region of the sensor while the sensor isviewed in plan view, each of the first and second leader lines includes:a first section extending in the second direction, wherein a first endof the first section is connected to a corresponding one of the firstand second end portions of the coil; a second section extending in thefirst direction, wherein a first end of the second section is connectedto a second end of the first section; and a third section extending inthe second direction, wherein a first end of the third section isconnected to a second end of the second section, the first substrate isa multilayer substrate including a plurality of layers including firstand second layers, the first coil and the second section are provided inthe first layer, and the second coil and the first and third sectionsare provided in the second layer.

A seventh aspect of the present disclosure provides a sensor including:a rectangle first substrate; and an integrated circuit, in which thefirst substrate is provided with a plurality of first coils eachincluding a first long-side portion extending in a first directionforming a predetermined angle larger than 0 degrees and smaller than 90degrees with respect to a long-side direction of the first substrate,and a plurality of second coils each including a second long-sideportion extending in a second direction crossing the first direction,and the integrated circuit, in operation, supplies different voltages orcurrents to each of the plurality of first and second coils according towhether the shape of each of the plurality of first and second coils isa parallelogram or a trapezoid.

An eighth aspect of the present disclosure provides a sensor including:a rectangle first substrate; and an integrated circuit, in which thefirst substrate is provided with a plurality of first coils eachincluding a first long-side portion extending in a first directionforming a predetermined angle larger than 0 degrees and smaller than 90degrees with respect to a long-side direction of the first substrate,and a plurality of second coils each including a second long-sideportion extending in a second direction crossing the first direction,the integrated circuit includes a processor and a memory storinginstructions and information indicating whether each of a plurality ofintersections formed by each of the plurality of first coils and each ofthe plurality of second coils is positioned on a center of a detectionregion, and when the processor executes the instructions stored in thememory, the processor causes the integrated circuit to detect a firstintersection closest to a position of a stylus among the plurality ofintersections formed by each of the plurality of first coils and each ofthe plurality of second coils based on a level observed in each of theplurality of first and second coils, and determine whether the firstintersection is positioned on an edge portion of the detection regionbased on the information stored in the memory.

Advantageous Effects

According to the first aspect of the present disclosure, the firstsubstrate is arranged on the back side of the display panel. Therefore,although the connection points of the first and second leader lines andthe first coils are provided on the center portion of the detectionregion instead of the edge portion, the reduction in the visibility ofthe display apparatus caused by the first and second leader lines can besuppressed. In addition, the first and second leader lines can be freelywired. Therefore, the second substrate can be arranged such that the oneend portion extends at the right angle toward the outside from the oneside of the first substrate, and the reduction in the arrangementefficiency of various circuits can also be suppressed.

According to the second aspect of the present disclosure, the length ofthe wiring formed on the second substrate can be uniform regardless ofthe extension direction of the leader line. Therefore, the correctionprocess in the controller can be performed based on only the differencein the wiring length on the first substrate.

According to the third and sixth aspects of the present disclosure, evenif the first coil is a separated coil not intersecting the second coil,the first coil can be connected to the wiring on the second substratethrough the first and second leader lines.

According to the fourth aspect of the present disclosure, signal changesof three or more coils to be used for coordinate calculation can besuitably acquired up to near the short-side portion. This canparticularly increase the accuracy of the position detection near theedge portion of the detection region.

According to the fifth and seventh aspects of the present disclosure,the distribution of the magnetic flux density can be equalized in theend portion of the detection region or in the entire detection region.

According to the eighth aspect of the present disclosure, whether or notthe position of the stylus is positioned in the edge portion of thedetection region can be determined without rotation transformation.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded view of a tablet terminal 1 according to a firstembodiment of the present disclosure.

FIG. 2A is a side view of the tablet terminal 1, and FIG. 2B is a rearview of the tablet terminal 1.

FIG. 3 is a schematic cross-sectional view of a sensor 13 according tothe first embodiment of the present disclosure.

FIG. 4 is a diagram illustrating a specific configuration of wiringincluded in a wiring layer L1 of the sensor 13 according to the firstembodiment of the present disclosure.

FIG. 5 is a diagram illustrating a specific configuration of wiringincluded in a wiring layer L2 of the sensor 13 according to the firstembodiment of the present disclosure.

FIG. 6 is a diagram illustrating a specific configuration of wiringincluded in a wiring layer L3 of the sensor 13 according to the firstembodiment of the present disclosure.

FIG. 7 is a diagram illustrating a specific configuration of wiringincluded in a wiring layer L4 of the sensor 13 according to the firstembodiment of the present disclosure.

FIG. 8 is a diagram describing a position detection process performed byan integrated circuit 20 according to the first embodiment of thepresent disclosure.

FIG. 9 is a flow chart of the position detection process performed bythe integrated circuit 20 according to the first embodiment of thepresent disclosure.

FIG. 10 is a diagram in which coils 40 a and 40 b illustrated in FIGS. 4to 7 are placed and illustrated on top of each other.

FIG. 11 is a diagram in which the coils 40 a and 40 b illustrated inFIGS. 4 to 7 are placed and illustrated on top of each other.

FIG. 12A is a diagram illustrating an example in which an adjustmentportion A1 is provided on an acute angle portion SAa of the coil 40 a,and FIG. 12B is a diagram illustrating an example in which an adjustmentportion A2 is provided on an obtuse angle portion OAa of the coil 40 a.

FIG. 13 is a diagram illustrating a specific configuration of the wiringincluded in the wiring layer L1 of the sensor 13 according to a secondembodiment of the present disclosure.

FIG. 14 is a diagram illustrating a specific configuration of the wiringincluded in the wiring layer L2 of the sensor 13 according to the secondembodiment of the present disclosure.

FIG. 15 is a diagram describing an outline of a position detectionprocess performed by the integrated circuit 20 according to a thirdembodiment of the present disclosure.

FIGS. 16A and 16B are diagrams illustrating two tables stored in advancein a memory in the integrated circuit 20 according to the thirdembodiment of the present disclosure.

FIG. 17 is an enlarged view of part of FIG. 15.

FIG. 18 is a flow chart of the position detection process performed bythe integrated circuit 20 according to the third embodiment of thepresent disclosure.

FIG. 19 is a diagram illustrating a state in which a flexible substrateand a controller are diagonally arranged.

DETAILED DESCRIPTION

Hereinafter, embodiments of the present disclosure will be described indetail with reference to the attached drawings.

FIG. 1 is an exploded view of a tablet terminal 1 according to a firstembodiment of the present disclosure. In addition, FIG. 2A is a sideview of the tablet terminal 1, and FIG. 2B is a rear view of the tabletterminal 1. In FIGS. 1 and 2A, an upper side corresponds to a displaysurface (touch surface) of the tablet terminal 1, and a lower sidecorresponds to a back surface of the tablet terminal 1.

As illustrated in FIGS. 1 and 2, the tablet terminal 1 has a structureincluding, from a back side, a shield plate 11, a spacer 12, a sensor13, a display panel 16, and a glass 18 that are layered in a displaymodule back surface cover 10 in a bathtub shape in which the back sideis closed. Among these, side surfaces of at least the sensor 13 and thedisplay panel 16 are covered by a display module frame 17 for protectionand fixation. The display module frame 17 is, for example, an adhesivetape. Although not illustrated, the tablet terminal 1 further includes ahousing that covers the entire tablet terminal 1 (including anintegrated circuit 20 and a bent substrate 21 described later) exceptthe surface of the glass 18. The surface of the glass 18 provides adisplay surface and a touch surface of the tablet terminal 1.

As illustrated in FIGS. 2A and 2B, the integrated circuit 20(controller) that provides a position detection apparatus along with thesensor 13 is installed on the back surface of the display module backsurface cover 10. The integrated circuit 20 includes a processor 20 a(processing circuit) that plays a role of controlling the entire tabletterminal 1 and a memory 20 b storing applications or instructions that,when executed by the processor 20 a, cause the integrated circuit toperform the acts described herein, a control circuit of the displaypanel 16, and the like are also arranged on the back surface of thedisplay module back surface cover 10. A region A illustrated in FIG. 2Brepresents a region in which the circuits can be arranged.

The tablet terminal 1 also includes the bent substrate 21 (secondsubstrate) for connecting the integrated circuit 20 and the sensor 13.The bent substrate 21 is, for example, a flexible substrate or aflexible printed circuit (FPC) formed by a thin plastic film, and thebent substrate 21 can be bent. This property is used to arrange the bentsubstrate 21 in the tablet terminal 1 in a state in which the bentsubstrate 21 is bent so as to enfold one side of the sensor 13 and thedisplay panel 16 as illustrated in FIG. 2A. One end of the bentsubstrate 21 is introduced into the display module back surface cover 10through an opening portion 10 a of the display module back surface cover10 illustrated in FIG. 1 and is connected to terminals 42 a and 42 b(described later) of the sensor 13. The other end of the bent substrate21 is connected to the integrated circuit 20 on the back surface of thedisplay module back surface cover 10.

The sensor 13 and the integrated circuit 20 provide the positiondetection apparatus in the EM system or the EMR (registered trademark)system and play a role of detecting the position of a stylus 2 (positionindicator) in a predetermined detection region. The detection region isa rectangle region set to have an area slightly larger than a displayregion of the display panel 16 described later and is arranged tooverlap the entire display region. The integrated circuit 20 detects,through the sensor 13, a pen signal (alternating magnetic field)transmitted by the stylus 2 to thereby detect the position of the stylus2 in the detection region. Furthermore, in the case where the integratedcircuit 20 corresponds to the EMR (registered trademark) system, theintegrated circuit 20 also executes a process of transmitting anelectromagnetic wave through the sensor 13 to generate power in thestylus 2. In this case, the stylus 2 uses the generated power totransmit the pen signal. Other details of the sensor 13 and theintegrated circuit 20 (particularly, structure of sensor 13 and specificmethod of position detection of integrated circuit 20) will be describedin detail later.

The display panel 16 is a display apparatus including liquid crystal,organic electroluminescence (EL), electronic paper, or the like. Thespecific type of the display panel 16 is not particularly limited.Specific display content of the display panel 16 is controlled by theprocessor and the control circuit. Although not illustrated, the displaypanel 16 includes the rectangle display region including a plurality ofpixels arranged in a matrix and includes a bezel region set around thedisplay region. Wiring for connecting the pixels to the control circuitis arranged in the bezel region.

Here, the arrangement of the sensor 13 (substrate 13A described later)on the back side of the display panel 16 is a feature of the presentdisclosure. The arrangement can be adopted to prevent the visibility ofthe display panel 16 from being reduced by the existence of leader lines41 a and 41 b of coils 40 a and 40 b described later even if the leaderlines 41 a and 41 b are provided on a center portion of the detectionregion. If the leader lines 41 a and 41 b can be provided on the centerportion of the detection region, the region (the invalid area) in whichthe position of the stylus 2 positioned around the detection regioncannot be detected can be reduced, and as a result, the bezel region canalso be reduced. Therefore, in the present embodiment, the leader lines41 a and 41 b are provided on the center portion of a detection region Tas described in detail later with reference to FIGS. 4 to 7.

The shield plate 11 is a magnetic body arranged on the back surface ofthe sensor 13, and the shield plate 11 functions as an electromagneticshield for preventing the electromagnetic wave generated by the sensor13 from being leaked to the back side. In addition, the shield plate 11also plays a role of a magnetic path of a magnetic flux generated by thesensor 13. The spacer 12 is, for example, a double-sided tape, and thespacer 12 plays a role of insulation between the wiring provided in thesensor 13 and the shield plate 11 and plays a role of fixing the sensor13 to the shield plate 11.

Hereinafter, the details of the sensor 13 and the integrated circuit 20will be described with reference to FIGS. 3 to 9.

FIG. 3 is a schematic cross-sectional view of the sensor 13. Asillustrated in FIG. 3, the sensor 13 includes the rectangle multilayersubstrate 13A (first substrate) formed by laminating, from a displaysurface side, a wiring layer L1 (first layer), an insulating layer 30, awiring layer L2 (second layer), an insulating layer 31, a wiring layerL3 (third layer), an insulating layer 32, and a wiring layer L4. Thewiring layers L1 and L4 are outermost layers, and the wiring layers L2and L3 are inner layers that are not outermost layers.

The wiring in the wiring layer L1 is connected to the wiring in thewiring layer L2 through a via conductor 33 passing through theinsulating layer 30. Similarly, the wiring in the wiring layer L3 isconnected to the wiring in the wiring layer L4 through a via conductor34 passing through the insulating layer 32. In addition, the wiring inthe wiring layer L1 is connected to the wiring in the wiring layer L4through a via conductor 35 passing through the insulating layers 30 to32 and the wiring layers L2 and L3.

FIGS. 4 to 7 are diagrams illustrating specific configurations of thewiring included in the wiring layers L1 to L4, respectively. Note thatan X-axis direction and a Y-axis direction illustrated in the drawingsdenote a long-side direction and a short-side direction of the substrate13A, respectively. In addition, an A-axis direction is a direction(first direction) at a predetermined angle larger than 0 degrees andsmaller than 90 degrees with respect to the long-side direction of thesubstrate 13A, and a B-axis direction is a direction (second direction)crossing the A-axis direction. Typically, as illustrated in FIGS. 4 to7, the A-axis direction and the X-axis direction form an angle of 45degrees, and the A-axis direction and the B-axis direction areorthogonal to each other. However, the specific directions of the A-axisdirection and the B-axis direction are not limited to these. Forexample, the B-axis direction and the Y-axis direction may not coincidewith each other.

In the following description, the coordinate system including the X-axisdirection and the Y-axis direction may be referred to as a “normalcoordinate system,” and the coordinate system including the A-axisdirection and the B-axis direction may be referred to as a “diagonalcoordinate system.” The rectangle with vertices at four coordinates (X1,Y1), (X2, Y1), (X1, Y2), and (X2, Y2) in the illustrated normalcoordinate system represents the detection region T of the sensor 13.

First, with reference to FIGS. 4 and 5, a plurality of coils 40 a areformed in the wiring layers L1 and L2. Each of the plurality of coils 40a typically has a substantially parallelogram shape surrounded bylong-side portions LEa1 and LEa2 extending in the A-axis direction andtwo short-side portions SEa extending in the X-axis direction. However,some of the coils 40 a have a substantially trapezoid shape surroundedby long-side portions LEa1 and LEa2 extending in the A-axis direction, ashort-side portion SEa extending in the X-axis direction, and ashort-side portion SEa extending in the Y-axis direction. Furthermore,two coils 40 a positioned at two parts among the four corners of thesubstrate 13A have a substantially triangle shape surrounded by along-side portion LEa1 extending in the A-axis direction, a short-sideportion SEa extending in the X-axis direction, and a short-side portionSEa extending in the Y-axis direction.

Main sections of each coil 40 a are formed in the wiring layer L2, andsome sections are formed in the wiring layer L1. The sections formed inthe wiring layer L1 and the sections formed in the wiring layer L2 areconnected to each other through the via conductors 33 indicated by blackcircles in FIGS. 4 and 5. The sections formed in the wiring layer L1include sections overlapping adjacent coils 40 a (first overlappingportions OLa illustrated in FIG. 4). Therefore, the plurality of coils40 a are arranged such that two adjacent coils 40 a overlap in planview.

The long-side portion LEa1 (first long-side portion) of each coil 40 ais disconnected in the middle of the section formed in the wiring layerL2. Two open ends generated by the disconnection provide end portionsEN1 and EN2 (first and second end portions) of the coils 40 a, and theend portions EN1 and EN2 are connected to corresponding leader lines 41a (described later).

Next, with reference to FIGS. 6 and 7, a plurality of coils 40 b areformed in the wiring layers L3 and L4. Each of the plurality of coils 40b typically has a substantially parallelogram shape surrounded bylong-side portions LEb1 and LEb2 extending in the B-axis direction andtwo short-side portions SEb extending in the X-axis direction. However,some of the coils 40 b have a substantially trapezoid shape surroundedby long-side portions LEb1 and LEb2 extending in the B-axis direction, ashort-side portion SEb extending in the X-axis direction, and ashort-side portion SEb extending in the Y-axis direction. Furthermore,two coils 40 b positioned on two parts among the four corners of thesubstrate 13A have a substantially triangle shape surrounded by along-side portion LEb1 extending in the B-axis direction, a short-sideportion SEb extending in the X-axis direction, and a short-side portionSEb extending in the Y-axis direction.

Main sections of each coil 40 b are formed in the wiring layer L3, andsome sections are formed in the wiring layer L4. The sections formed inthe wiring layer L3 and the sections formed in the wiring layer L4 areconnected to each other through the via conductors 34 indicated by blackcircles in FIGS. 6 and 7. The sections formed in the wiring layer L4include sections overlapping adjacent coils 40 b (second overlappingportions OLb illustrated in FIG. 7). Therefore, the plurality of coils40 b are arranged such that two adjacent coils 40 b overlap in planview.

The long-side portion LEb1 (second long-side portion) of each coil 40 bis disconnected in the middle of the section formed in the wiring layerL3. Two open ends generated by the disconnection provide end portionsEN1 and EN2 of the coil 40 b, and the end portions EN1 and EN2 areconnected to corresponding leader lines 41 b (described later).

With reference again to FIG. 4, the wiring layer L1 is further providedwith a plurality of leader lines 41 a and 41 b and a terminal groupincluding a plurality of terminals 42 a and 42 b. All of them arearranged in the detection region T. The terminals 42 a and 42 b arearranged side by side in the X-axis direction near one long side of thesubstrate 13A.

Here, the bent substrate 21 is arranged such that one end portionextends at a right angle toward the outside of the substrate 13A fromone long side of the substrate 13A in plan view as illustrated in FIG.4. In addition, a plurality of terminals 23 corresponding one to onewith the plurality of terminals 42 a and 42 b is provided on one endportion of the bent substrate 21. Each terminal 23 is individuallyconnected to the integrated circuit 20 through wiring 22 formed on thebent substrate 21 and is electrically connected to a corresponding oneof the plurality of terminals 42 a and 42 b by crimping. According tothe structure, each of the plurality of leader lines 41 a and 41 b isindividually connected to the integrated circuit 20 through thecorresponding one of the plurality of terminals 42 a and 42 b, thecorresponding terminal 23, and the corresponding wiring 22.

Note that the bent substrate 21 and the substrate 13A may be formed asan integrated substrate. In this case, the plurality of terminals 42 aand 42 b and the plurality of terminals 23 may not be provided, and eachof the plurality of leader lines 41 a and 41 b may be directly connectedto the corresponding wiring 22.

The plurality of leader lines 41 a (first and second leader lines) areprovided to correspond to the end portions EN1 and EN2 of the coils 40a, respectively. Therefore, the number of leader lines 41 a is twice thenumber of coils 40 a. Each leader line 41 a is connected to acorresponding one of the end portion EN1 and the end portion EN2 throughthe via conductor 33 indicated by a black circle in FIGS. 4 and 5. Inthis way, the end portions EN1 and EN2 of each coil 40 a are connectedto the integrated circuit 20.

The plurality of leader lines 41 b are provided to correspond to the endportions EN1 and EN2 of the coils 40 b, respectively. Therefore, thenumber of leader lines 41 b is twice the number of coils 40 b. Eachleader line 41 b is once drawn out to the wiring layer L4 through thevia conductor 35 indicated by a black rectangle in FIGS. 4 to 7, drawnaround to the position of corresponding one of the end portion EN1 andthe end portion EN2 in the wiring layer L4, and then connected to thecorresponding one of the end portion EN1 and the end portion EN2 throughthe via conductor 34 indicated by a black circle in FIGS. 6 and 7. Inthis way, the end portions EN1 and EN2 of each coil 40 b are alsoconnected to the integrated circuit 20.

Here, some of the plurality of leader lines 41 a and 41 b include bentportions extending in directions different from the A-axis direction andthe B-axis direction (for example, partial wiring 41 aa, 41 ab, and 41ba illustrated in FIG. 4 and partial wiring 41 bb illustrated in FIG.7). The existence of the bent portions can be permitted to increase thedegree of freedom of the wiring layout and efficiently arrange theleader lines 41 a and 41 b. In addition, the difference in wiring lengthbetween the leader lines 41 a and 41 b can also be reduced. Note thatalthough the bent portions are provided on the leader lines 41 a and 41b in the present embodiment, bent portions extending in directionsdifferent from the X-axis direction and the Y-axis direction may beprovided on the terminals 42 a and 42 b. Similar advantageous effectscan also be obtained in this way.

FIG. 8 is a diagram describing a position detection process performed bythe integrated circuit 20 using the sensor 13 with the structure asdescribed above. In addition, FIG. 9 is a flow chart of the positiondetection process performed by the integrated circuit 20. Hereinafter,the position detection process using the sensor 13 will be described indetail with reference to the drawings.

First, the integrated circuit 20 repeats a process of sequentiallyscanning the plurality of coils 40 a and 40 b to acquire a detectionlevel (received intensity) of a pen signal in each of the plurality ofcoils 40 a and 40 b (S1). Next, the integrated circuit 20 corrects theacquired detection level based on the wiring length of each of theleader lines 41 a and 41 b (S2). The correction process is a necessaryprocess because the wiring length of each of the leader lines 41 a and41 b is not constant. That is, the longer the wiring length of theleader lines 41 a and 41 b, the larger the wiring resistance. Therefore,the level of the pen signal reaching the integrated circuit 20 becomessmall. Thus, the correction process of the detection level based on thewiring length of each of the leader lines 41 a and 41 b is incorporatedin advance into the integrated circuit 20.

Next, the integrated circuit 20 uses a three-point method or afour-point method to detect coordinates (a, b) in the diagonalcoordinate system indicating a position P of the stylus 2 based on thedetection level after the correction (S3). In relation to the A-axis,the three-point method is, for example, a system for generating apredetermined interpolation curve based on the detection levels of thepen signals in three coils 40 a including the coil 40 a with the highestdetection level of the pen signal among the plurality of coils 40 a andother two coils 40 a positioned on both sides of the coil 40 a and thensetting the vertex of the interpolation curve as the A-axis coordinate.In the four-point method, the detection level of another coil 40 a (forexample, a coil 40 a with the higher detection level of the two coils 40a positioned on both sides of the three coils 40 a) is further used togenerate the interpolation curve. This is similar for the B-axis.

The integrated circuit 20 that has acquired the coordinates (a, b) inthe diagonal coordinate system uses a rotation transformation indicatedin the following Equation (1) to convert the acquired coordinates (a, b)in the diagonal coordinate system into coordinates (x, y) in the normalcoordinate system (S4). Here, e indicated in Equation (1) is an angle(for example, 45°) formed by the X-axis and the A-axis as illustrated inFIG. 8. Furthermore, Equation (1) is formulated on the assumption thatthe A-axis and the B-axis are orthogonal to each other, and in a casewhere the A-axis and the B-axis are not orthogonal to each other, theangle formed by the A-axis and the B-axis needs to be taken into accountto modify Equation (1).

$\begin{matrix}\left\lbrack {{Math}.\mspace{14mu} 1} \right\rbrack & \; \\{\begin{pmatrix}x \\y\end{pmatrix} = {\begin{pmatrix}{\cos \; \theta} & {{- \sin}\; \theta} \\{\sin \; \theta} & {\cos \; \theta}\end{pmatrix}\begin{pmatrix}a \\b\end{pmatrix}}} & (1)\end{matrix}$

The integrated circuit 20 is configured to output, to the processor, thecoordinates (x, y) in the normal coordinate system obtained by theconversion (S4). As a result, the integrated circuit 20 can notify theprocessor of the coordinates (x, y) in the normal coordinate system.

As described above, according to the present embodiment, the substrate13A is arranged on the back side of the display panel 16. Therefore,although the connection points (end portions EN1 and EN2) of the leaderlines 41 a and 41 b and the coils 40 a and 40 b are provided on thecenter portion of the detection region T instead of the edge portion,the reduction in the visibility of the display panel 16 caused by theleader lines 41 a and 41 b can be suppressed.

In addition, according to the present embodiment, the leader lines 41 aand 41 b can be freely wired, and the bent substrate 21 can be arrangedsuch that one end portion extends at a right angle toward the inside ofthe substrate 13A from one side of the substrate 13A in plan view.Therefore, the bent substrate 21 and the integrated circuit 20 can bestraightly arranged on the back surface of the display module backsurface cover 10 as illustrated in FIG. 2B, and this can suppress thereduction in the arrangement efficiency of various circuits includingthe integrated circuit 20 as can be understood by comparing the region Aillustrated in FIG. 2B and the region A illustrated in FIG. 19.

In addition, according to the present embodiment, the terminals 42 a and42 b are arranged side by side in the X-axis direction near one longside of the substrate 13A, and the length of the wiring 22 formed on thebent substrate 21 can be uniform regardless of the extension directionof the leader lines 41 a and 41 b. Therefore, the correction process ofS2 illustrated in FIG. 9 can be performed based on only the differencein the wiring length on the substrate 13A.

This advantageous effect will be described in detail. In general, acompany different from the vendor of the sensor 13 and the integratedcircuit 20 assembles the tablet terminal 1, and the bent substrate 21 isprepared by the company that performs the assembly. Therefore, it ispreferable to allow using a simple bent substrate 21 with uniform lengthof wiring 22. In this way, the vendor of the sensor 13 and theintegrated circuit 20 can design the correction process at S2illustrated in FIG. 9 without taking into account the difference inlength of the wiring 22 formed on the bent substrate 21. According tothe present embodiment, the simple bent substrate 21 can be used, andthe vendor of the sensor 13 and the integrated circuit 20 can design thecorrection process at S2 illustrated in FIG. 9 without taking intoaccount the difference in length of the wiring 22 formed on the bentsubstrate 21.

Hereinafter, other features of the tablet terminal 1 according to thepresent embodiment and advantageous effects attained by the featureswill be described.

FIGS. 10 and 11 are diagrams in which the coils 40 a and 40 billustrated in FIGS. 4 to 7 are placed and illustrated on top of eachother. However, it is difficult to understand this if all of the coils40 a and 40 b are placed and illustrated on top of each other.Therefore, half of the coils 40 a and half of the coils 40 b areillustrated in FIGS. 10 and 11. In addition, the coils 40 a areindicated by solid lines, and the coils 40 b are indicated by brokenlines.

As illustrated in FIGS. 10 and 11, each of the plurality of coils 40 aand 40 b according to the present embodiment is formed such that atleast part of the short-side portion SEa of the coil 40 a and at leastpart of the short-side portion SEb of the coil 40 b overlap in planview. Particularly, the coils 40 a and 40 b are formed such that theshort-side portion SEa of each coil 40 a extending in the X-axisdirection completely overlaps the short-side portion SEb of one of theplurality of coils 40 b.

According to the configuration, the integrated circuit 20 can suitablyacquire signal changes of three or more coils 40 a and 40 b used for thecoordinate calculation, up to near each short-side portion. Therefore,the coordinate calculation can be performed by the three-point methodusing three or more coils (or the four-point method using four or morecoils) even near the edge portion of the detection region T where thecoordinate calculation is conventionally performed by the two-pointmethod. This can increase the coordinate accuracy of the case in whichthe stylus 2 is positioned on the end portion of the detection region T(near the side). In this case, the integrated circuit 20 can beconfigured to perform the coordinate calculation by using both of theresults of the detection by three coils 40 a and the results of thedetection by three coils 40 b to further increase the coordinateaccuracy. Additionally, in the examples of FIGS. 10 and 11, the coils 40a and 40 b are formed such that the short-side portion SEa of each coil40 a extending in the X-axis direction completely overlaps theshort-side portion SEb of one of the plurality of coils 40 b, and thecoordinate system can be further increased.

Furthermore, as illustrated at positions of X-axis coordinates X3 and X4in FIG. 11, the plurality of coils 40 a and 40 b according to thepresent embodiment are formed such that an acute angle portion SAa ofthe parallelogram coil 40 a and an obtuse angle portion OAb of theparallelogram coil 40 b overlap in plan view. This is similar for anobtuse angle portion OAa of the parallelogram coil 40 a and an acuteangle portion SAb of the parallelogram coil 40 b. Note that the acuteangle portions SAa and SAb and the obtuse angle portions OAa and OAb arealso illustrated in FIGS. 4 to 7. In addition, the integrated circuit 20according to the present embodiment is configured to supply the currentat the same time to the acute angle portion and the obtuse angle portion(that is, the coil including the acute angle portion and the coilincluding the obtuse angle portion) arranged at the same position inplan view when transmitting the electromagnetic wave through the sensor13.

When the integrated circuit 20 corresponding to the EMR (registeredtrademark) system transmits the electromagnetic wave through the sensor13, the magnetic flux density is high in the acute angle portions SAaand SAb, and the magnetic flux density is low in the obtuse angleportions OAa and OAb. Therefore, there may be a section with nonuniformmagnetic flux density in the end portion of the detection region T or inthe entire detection region T. However, according to the configuration,the sections with high magnetic flux density (acute angle portions SAaand SAb) and the sections with low magnetic flux density (obtuse angleportions OAa and OAb) are positioned at the same places in plan view.Therefore, the distribution of the magnetic flux density can beequalized in the end portion of the detection region T or in the entiredetection region T.

Note that the uniformity of the magnetic flux density can also beattained by other configurations. Hereinafter, the other configurationswill be described in detail.

FIG. 12A is a diagram illustrating an example in which an adjustmentportion A1 is provided on the acute angle portion SAa of the coil 40 a.The adjustment portion A1 includes a short circuit wire of the acuteangle portion SAa provided between the long-side portion (long-sideportion LEa1 in this case) and the short-side portion SEa included inthe acute angle portion SAa. The adjustment portion A1 can be providedon each acute angle portion of the coils 40 a and 40 b to reduce thedifference in the magnetic flux density at the corner portions(particularly, difference from the obtuse angle portion). Therefore, thedistribution of the magnetic flux density can be equalized.

FIG. 12B is a diagram illustrating an example in which an adjustmentportion A2 is provided on the obtuse angle portion OAa of the coil 40 a.The adjustment portion A2 includes a line segment connecting: an endportion of the long-side portion (in this case, long-side portion LEa2)included in the obtuse angle portion OAa, the end portion obtained byextending the long-side portion toward the outside of the detectionregion T from the obtuse angle portion OAa; and an end portion of theshort-side portion SEa included in the obtuse angle portion OAa, the endportion obtained by shortening the short-side portion SEa toward thecorresponding acute angle portion. The adjustment portion A2 can beprovided on each obtuse angle portion of the coils 40 a and 40 b toreduce the difference in the magnetic flux density at the cornerportions (particularly, difference from the acute angle portion).Therefore, the distribution of the magnetic flux density can beequalized.

Next, a second embodiment of the present disclosure will be described.The configuration of the sensor 13 of the tablet terminal 1 according tothe present embodiment is different from that of the tablet terminal 1according to the first embodiment. The second embodiment is similar tothe first embodiment in other respects. Therefore, the same referencesigns are provided to the same components, and the differences from thefirst embodiment will be mainly described.

FIGS. 13 and 14 are diagrams illustrating a specific configuration ofthe wiring included in the wiring layers L1 and L2 of the sensor 13according to the present embodiment. The sensor 13 according to thepresent embodiment includes a plurality of coils 50 a and 50 b in placeof the plurality of coils 40 a and 40 b. The plurality of coils 50 a and50 b are different from the sensor 13 according to the first embodimentin that the coils 50 a do not overlap with each other in plan view, andthe coils 50 b do not overlap with each other in plan view. According tothe configuration, the coils 50 a are formed only in the single wiringlayer L2, and the coils 50 b are formed only in the single wiring layerL1 in the present embodiment. Note that it is obvious that the coils 50a may be formed in the wiring layer L1, and the coils 50 b may be formedin the wiring layer L2.

Leader lines 51 a of the coil 50 a and leader lines (not illustrated) ofthe coil 50 b are formed in regions not interfering with the coils 50 aand 50 b in the wiring layers L1 and L2. As a result, the wiring layersL3 and L4 and the insulating layers 31 and 32 among the layers of thesubstrate 13A illustrated in FIG. 3 are eliminated, and the wiringlayers L1 and L2 are the outermost layers in the present embodiment. Inaddition, the via conductors 34 and 35 illustrated in FIG. 3 are notprovided on the sensor 13 according to the present embodiment.

FIGS. 13 and 14 illustrate only four leader lines 51 a connected to twocoils 50 a 1 and 50 a 2 among the plurality of leader lines 51 aprovided in association with the coils 50 a. As illustrated in FIGS. 13and 14, one end of each of the four leader lines 51 a is connected toeach of four terminals 52 a provided in a region corresponding to theinside of a coil 50 b 1 that is one of the plurality of coils 50 b. Thefour terminals 52 a are arranged side by side in the X-axis directionnear one long side of the substrate 13A as in the first embodiment andare connected to the terminals 23 (see FIG. 4) formed on the bentsubstrate 21. Although not illustrated, this is similar for theterminals 52 a connected to the other leader lines 51 a and theterminals connected to the leader lines of the coils 50 b.

As can be understood from FIGS. 13 and 14, the coil 50 a 1 includes asection in which the corresponding terminal 52 a overlaps the coil 50 b1 formed inside of the coil 50 a 1 in plan view. Two leader lines 51 aconnected to the coil 50 a 1 are formed to extend in the B-axisdirection in a region corresponding to the inside of the coil 50 b 1 inplan view and are connected to the end portions EN1 and EN2 of the coil50 a 1 through the via conductor 33, respectively.

On the other hand, as can be understood from FIGS. 13 and 14, the coil50 a 2 does not include a section in which the corresponding terminal 52a overlaps the coil 50 b 1 formed inside of the coil 50 a 2 in planview. Hereinafter, the coil will be referred to as a “separated coil.”Two leader lines 51 a connected to the separated coil 50 a 2 cannot beconnected to the coil 50 a 2 in the region corresponding to the insideof the coil 50 b 1 in plan view. Therefore, the connection of the leaderline 51 a and the coil 50 a 2 is realized through the wiring layer L2 inthe middle. Hereinafter, the details will be described.

Each of the two leader lines 51 a connected to the coil 50 a 2 includes:a first section 51 a 1 extending in the B-axis direction, in which oneend is connected to a corresponding one of the end portions EN1 and EN2of the coil 50 a 2; a second section 51 a 2 extending in the A-axisdirection, in which one end is connected to the other end of the firstsection 51 a 1; and a third section 51 a 3 extending in the B-axisdirection, in which one end is connected to the other end of the secondsection 51 a 2.

The third section 51 a 3 is a section formed in the region correspondingto the inside of the coil 50 b 1 in plan view. The other end of thethird section 51 a 3 is connected to the corresponding terminal 52 a.

The second section 51 a 2 is a section formed in the regioncorresponding to the inside of the coil 50 a 3 illustrated in FIG. 14.The coil 50 a 3 is a coil including a section overlapping the coil 50 b1 in plan view among the plurality of coils 50 a and including a sectionoverlapping the coil 50 b 2 including a section overlapping the coil 50a 2 in plan view among the plurality of coils 50 b. In the exampleillustrated in FIGS. 13 and 14, the coil 50 a 1 also corresponds to thiscondition, and the coil 50 a 1 may also serve as the coil 50 a 3. Theother end of the second section 51 a 2 is connected to one end of thethird section 51 a 3 through the via conductor 33 in the region wherethe coils 50 b 1 and 50 a 3 overlap.

The first section 51 a 1 is a section formed in the region correspondingto the inside of the coil 50 b 2. The other end of the first section 51a 1 is connected to one end of the second section 51 a 2 through the viaconductor 33 in the region where the coils 50 a 2 and 50 b 2 overlap.One end of the first section 51 a 1 is connected to the correspondingone of the end portions EN1 and EN2 of the coil 50 a 2 through the viaconductor 33.

As described above, according to the present embodiment, the first tothird sections 51 a 1 to 51 a 3 are provided on the leader line 51 a,and the separated coil 50 a 2 can be connected to the leader line 51 a.Therefore, the separated coil 50 a 2 can be connected to the wiring 22(see FIG. 4) on the bent substrate 22 while using a two-layer substratethat is not a multilayer substrate. Note that although the presentembodiment focuses on the separated coil of the coil 50 a, the presentembodiment similarly applies to the separated coil of the coil 50 b.

Note that a similar advantageous effect can be realized by providing oneor more wiring layers different from the wiring layers provided with thecoils 50 a and 50 b and arranging the leader lines of the coils 50 a and50 b in the one or more wiring layers. The configuration is none otherthan a configuration obtained by changing the shapes of the coils 40 aand 40 b into the same shapes as the coils 50 a and 50 b in the firstembodiment.

Next, a third embodiment of the present disclosure will be described. Inthe tablet terminal 1 according to the present embodiment, the operationof the integrated circuit 20 is different from that of the tabletterminal 1 according to the first embodiment. The third embodiment issimilar to the first embodiment in other respects. Therefore, the samereference signs are provided to the same components, and the differencesfrom the first embodiment will be mainly described.

FIG. 15 is a diagram describing an outline of a position detectionprocess performed by the integrated circuit 20 according to the presentembodiment. Black dots and white dots illustrated in FIG. 15 representintersections IS of the coils 40 a and 40 b. The intersections ISindicated by the white dots are positioned on an edge portion of thedetection region T. The integrated circuit 20 according to the presentembodiment determines whether or not the stylus 2 is positioned on theedge portion of the detection region T when the integrated circuit 20performs the position detection of the stylus 2 based on the level ofthe pen signal. In addition, when the integrated circuit 20 determinesthat the stylus 2 is positioned on the edge portion of the detectionregion T, the integrated circuit 20 uses the method described in thefirst embodiment (method based on rotation transformation) to obtain thecoordinates (x, y) in the normal coordinate system. On the other hand,when the integrated circuit 20 determines that the stylus 2 is notpositioned on the edge portion of the detection region T (that is, whenthe integrated circuit 20 determines that the stylus 2 is positioned onthe center portion of the detection region T), the integrated circuit 20uses a simpler method to obtain the coordinates (x, y) in the normalcoordinate system.

FIGS. 16A and 16B are diagrams illustrating two tables stored in advancein the memory 21 b in the integrated circuit 20 according to the presentembodiment. The table illustrated in FIG. 16A is a table associating andstoring, for each intersection IS, the coordinates in the diagonalcoordinate system, the coordinates in the normal coordinate system, andan edge portion flag indicating whether or not the intersection IS ispositioned on the edge portion of the detection region T. The table willbe referred to as an “intersection table.” On the other hand, the tableillustrated in FIG. 16B is a table associating and storing thedifference between the coordinates in the diagonal coordinate system andthe difference between the coordinates in the normal coordinate system.The table will be referred to as a “difference table.” The integratedcircuit 20 according to the present embodiment uses the tables toperform a process of converting the coordinates (a, b) in the diagonalcoordinate system into the coordinates (x, y) in the normal coordinatesystem.

FIG. 17 is an enlarged view of part of FIG. 15. In addition, FIG. 18 isa flow chart of the position detection process performed by theintegrated circuit 20 according to the present embodiment. Hereinafter,the position detection process performed by the integrated circuit 20according to the present embodiment will be described in detail withreference to the drawings. Note that in the following description, it isassumed that the position P illustrated in FIG. 17 is the currentposition of the stylus 2.

The process at S1 to S3 is as described in the first embodiment. Theintegrated circuit 20 that has detected the coordinates (a, b) of theposition P in the diagonal coordinate system at S3 then detects anintersection ISP that is the intersection IS closest to the coordinates(a, b) and acquires coordinates (a_(s), b_(s)) in the diagonalcoordinate system (S10). Furthermore, the integrated circuit 20 refersto the intersection table to determine whether or not the acquiredcoordinates (a_(s), b_(s)) are on the edge portion of the detectionregion T (S11 and S12). Specifically, the integrated circuit 20determines that the coordinates (a_(s), b_(s)) are on the edge portionof the detection region T if the edge portion flag stored in associationwith the coordinates (a_(s), b_(s)) in the intersection table is “True”and determines that the coordinates (a_(s), b_(s)) are not on the edgeportion of the detection region T if the edge portion flag is “False.”

If the integrated circuit 20 determines that the coordinates (a_(s),b_(s)) are on the edge portion at S12, the integrated circuit 20performs the rotation transformation to convert the coordinates (a, b)in the diagonal coordinate system into the coordinates (x, y) in thenormal coordinate system and outputs the coordinates (x, y) to theprocessor as in the first embodiment (S4).

On the other hand, the integrated circuit 20 that has determined thatthe coordinates (a_(s), b_(s)) are not on the edge portion at S12 firstacquires relative coordinates (Δa, Δb) indicating a relative position ofthe stylus 2 with respect to the intersection ISP in the diagonalcoordinate system (S13). As illustrated in FIG. 17, the relativecoordinate Δa corresponds to the difference between the coordinate a andthe coordinate a_(s), and the relative coordinate Δb corresponds to thedifference between the coordinate b and the coordinate b_(s).

Next, the integrated circuit 20 maps the coordinates (a_(s), b_(s)) inthe diagonal coordinate system on coordinates (x_(s), y_(s)) in thenormal coordinate system (S14). Specifically, the integrated circuit 20refers to the intersection table illustrated in FIG. 16A to acquire thecoordinates in the normal coordinate system corresponding to thecoordinates (a_(s), b_(s)) and acquires the coordinates as thecoordinates (x_(s), y_(s)). In addition, the integrated circuit 20 mapsthe relative coordinates (Δa, Δb) in the diagonal coordinate system onrelative coordinates (Δx, Δy) in the normal coordinate system (S15).Specifically, the integrated circuit 20 refers to the difference tableillustrated in FIG. 16B to acquire the relative coordinates in thenormal coordinate system corresponding to the relative coordinates (Δa,Δb) and acquires the relative coordinates as the relative coordinates(Δx, Δy).

Subsequently, the integrated circuit 20 calculates the coordinates (x,y) of the position P in the normal coordinate system based on theacquired coordinates (x_(s), y_(s)) and relative coordinates (Δx, Δy)and outputs the coordinates (x, y) to the processor (S16). Specifically,the integrated circuit 20 adds the relative coordinate Δx to thecoordinate x_(s) to acquire the X coordinate x of the position P andadds the relative coordinate Δy to the coordinate x_(s) to acquire the Ycoordinate y of the position P.

According to the present embodiment, the integrated circuit 20 candetermine whether or not the position of the stylus 2 is positioned onthe edge portion of the detection region T without the rotationtransformation. Therefore, when the stylus 2 is positioned at the centerof the detection region T, the simple method without rotationtransformation (S13 to S16) can be used to convert the coordinates (a,b) in the diagonal coordinate system into the coordinates (x, y) in thenormal coordinate system.

Although the preferred embodiments of the present disclosure have beendescribed, the present disclosure is not limited to the embodiments inany way, and it is obvious that the present disclosure can be carriedout in various modes without departing from the scope of the presentdisclosure.

For example, the integrated circuit 20 may be configured to supplydifferent voltages or currents to the plurality of coils (the coils 40 aand 40 b in the first and third embodiments and the plurality of coils50 a and 50 b in the second embodiment) according to the shapes(specifically, depending on whether the shape is, for example, aparallelogram, a trapezoid, or a triangle) of the plurality of coilswhen the integrated circuit 20 transmits the electromagnetic wave basedon the EMR (registered trademark) system from the sensor 13.Specifically, the integrated circuit 20 may be configured to supply arelatively large voltage or current to the parallelogram coil, supply arelatively medium voltage or current to the trapezoid coil, and supply arelatively large voltage or current to the triangle coil. Furthermore,in another example, the integrated circuit 20 may be configured toadjust, for each coil, at least one of the voltage and the current to besupplied to each coil according to the length of each of the pluralityof coils. Although the density of the generated magnetic flux may varyin each coil depending on the difference in the shape or the length ofthe coil even when the same voltage or current is supplied, thedifference in the magnetic flux density can be suppressed according tothe configuration, and the distribution of the magnetic flux density canbe equalized in the end portion of the detection region T or in theentire detection region T.

Furthermore, although all of the numbers of turns of the coils 40 a, 40b, 50 a, and 50 b are one in the embodiments, the number of turns of arelatively short coil among the coils (for example, the substantiallytrapezoid coil 40 a illustrated in FIGS. 4 and 5) may be larger than thenumber of turns of a relatively long coil (for example, thesubstantially parallelogram coil 40 a illustrated in FIGS. 4 and 5). Inthis way, the density of the magnetic flux generated in each coil can beuniform.

DESCRIPTION OF REFERENCE SYMBOLS

-   -   1 Tablet terminal    -   2 Stylus    -   10 Display module back surface cover    -   10 a Opening portion of display module back surface cover 10    -   11 Shield plate    -   12 Spacer    -   13 Sensor    -   13A Substrate    -   16 Display panel    -   17 Display module frame    -   18 Glass    -   20 Integrated circuit    -   21 Bent substrate    -   22 Wiring on bent substrate 21    -   23 Terminal on bent substrate 21    -   30 to 32 Insulating layer    -   33 to 35 Via conductor    -   40 a, 40 b, 50 a, 50 b, 50 a 1, 50 a 2, 50 a 3, 50 b 1, 50 b 2        Coil    -   41 a, 41 b, 51 a Leader line    -   41 aa, 41 ab, 41 bb Partial wiring    -   42 a, 42 b, 52 a Terminal of sensor 13    -   51 a 1 First section of leader line 51 a    -   51 a 2 Second section of leader line 51 a    -   51 a 3 Third section of leader line 51 a    -   A1, A2 Adjustment portion    -   EN1, EN2 End portion    -   IS, ISP Intersection    -   L1 to L4 Wiring layer    -   LEa1, LEa2, LEb1, LEb2 Long-side portion    -   OAa, OAb Obtuse angle portion    -   OLa First overlapping portion    -   OLb Second overlapping portion    -   SAa, SAb Acute angle portion    -   SEa, SEb Short-side portion    -   T Detection region

1. A sensor comprising: a first substrate which, in operation, isarranged on a back side of a display panel; a first coil extending in afirst direction at a predetermined angle larger than 0 degrees andsmaller than 90 degrees with respect to a long-side direction of thefirst substrate, the first coil including a first long-side portionprovided with a first end portion and second end portion; a second coilincluding a second long-side portion extending in a second directioncrossing the first direction; a first leader line including a first endand a second end, wherein the first end is connected to the first endportion of the first coil, and the second end is connected to wiring ona second substrate arranged to extend at a right angle toward an outsideof the sensor from one side of the first substrate; and a second leaderline including a first end connected to the second end portion of thefirst coil and a second end connected to the wiring on the secondsubstrate.
 2. The sensor according to claim 1, wherein: a terminal grouparranged side by side in the long-side direction of the first substrateis formed on the second substrate, and the second end of the firstleader line and the second end of the second leader line are connectedto the wiring on the second substrate through the terminal group.
 3. Thesensor according to claim 2, wherein: the terminal group is provided ona detection region of the sensor while the sensor is viewed in planview.
 4. The sensor according to claim 3, wherein: the first and secondleader lines include bent portions extending in directions differentfrom the first and second directions.
 5. The sensor according to claim3, wherein: at least some of a plurality of terminals included in theterminal group include bent portions extending in directions differentfrom the long-side direction of the first substrate and a short-sidedirection of the first substrate.
 6. The sensor according to claim 1,wherein: the first substrate is a multilayer substrate including aplurality of layers including a first layer, a second layer, and a thirdlayer, the first long-side portion is provided in the second layer, thesecond long-side portion is provided in the third layer, and the firstand second leader lines are provided in the first layer.
 7. The sensoraccording to claim 6, wherein: the first layer is an outermost layer ofthe plurality of layers, and at least one of the second and third layersis an inner layer of the plurality of layers.
 8. The sensor according toclaim 1, wherein: the first and second coils are formed such that atleast part of a short-side portion of the first coil and at least partof a short-side portion of the second coil overlap while the sensor isviewed in plan view.
 9. The sensor according to claim 8, wherein: thefirst substrate is a multilayer substrate including a plurality oflayers including a first layer, a second layer, and a third layer, thefirst long-side portion is provided in the second layer, the secondlong-side portion is provided in the third layer, the first and secondleader lines are provided in the first layer, a plurality of the firstcoils and a plurality of the second coils are formed on the firstsubstrate, each of the plurality of first coils includes a firstoverlapping portion overlapping an adjacent one of the first coils whilethe sensor is viewed in plan view, each of the plurality of second coilsincludes a second overlapping portion overlapping an adjacent one of thesecond coils while the sensor is viewed in plan view, and the firstoverlapping portion of each of the plurality of first coils or thesecond overlapping portion of each of the plurality of second coils isprovided in the first layer.
 10. The sensor according to claim 8,wherein: the first and second coils are formed such that an acute angleportion of the first coil and an obtuse angle portion of the second coiloverlap while the sensor is viewed in plan view.
 11. The sensoraccording to claim 10, further comprising: an integrated circuitconnected to the wiring on the second substrate, wherein the integratedcircuit, in operation, supplies a current at a same time to the acuteangle portion and the obtuse angle portion.
 12. The sensor according toclaim 1, wherein: the first and second coils include adjustment portionswhich, in operation, reduce a difference in magnetic flux density atcorner portions of the first substrate.
 13. The sensor according toclaim 1, wherein: a plurality of the first coils is formed on the firstsubstrate, and a number of turns of a relatively short first coil amongthe plurality of first coils is larger than a number of turns of arelatively long first coil among the plurality of first coils.
 14. Thesensor according to claim 1, further comprising: an integrated circuitconnected to the wiring on the second substrate, wherein: a plurality ofthe first coils with different lengths is formed on the first substrate,and the integrated circuit, in operation, adjusts, for each of theplurality of first coils, at least one of a voltage and a current to besupplied to each of the plurality of first coils.
 15. The sensoraccording to claim 2, wherein: each of the first and second leader linesis provided on a detection region of the sensor while the sensor isviewed in plan view.
 16. The sensor according to claim 15, wherein: eachof the first and second leader lines includes: a first section extendingin the second direction, wherein a first end of the first section isconnected to a corresponding one of the first and second end portions ofthe first coil, a second section extending in the first direction,wherein a first end of the second section is connected to a second endof the first section, and a third section extending in the seconddirection, wherein a first end of the third section is connected to asecond end of the second section, the first substrate is a multilayersubstrate including a plurality of layers including a first layer and asecond layer, the first coil and the second section are provided in thefirst layer, and the second coil and the first and third sections areprovided in the second layer.
 17. The sensor according to claim 16,wherein: the first coil is positioned on one of four corners of thefirst substrate.
 18. The sensor according to claim 17, wherein: thefirst coil is formed in a substantially triangular shape.
 19. A sensorcomprising: a rectangle first substrate; and an integrated circuit,wherein: the first substrate includes: a plurality of first coils eachincluding a first long-side portion extending in a first directionforming a predetermined angle larger than 0 degrees and smaller than 90degrees with respect to a long-side direction of the first substrate,and a plurality of second coils each including a second long-sideportion extending in a second direction crossing the first direction,and the integrated circuit, in operation, supplies different voltages orcurrents to each of the plurality of first and second coils according towhether the shape of each of the plurality of first and second coils isa parallelogram or a trapezoid.
 20. A sensor comprising: a rectanglefirst substrate; and an integrated circuit, wherein: the first substrateis provided with a plurality of first coils each including a firstlong-side portion extending in a first direction forming a predeterminedangle larger than 0 degrees and smaller than 90 degrees with respect toa long-side direction of the first substrate, and a plurality of secondcoils each including a second long-side portion extending in a seconddirection crossing the first direction, the integrated circuit includesa processor and a memory storing instructions and information indicatingwhether each of a plurality of intersections formed by each of theplurality of first coils and each of the plurality of second coils ispositioned on a center of a detection region, and when the processorexecutes the instructions stored in the memory, the processor causes theintegrated circuit to: detect a first intersection closest to a positionof a stylus among the plurality of intersections formed by each of theplurality of first coils and each of the plurality of second coils basedon a level observed in each of the plurality of first and second coils,and determine whether the first intersection is positioned on an edgeportion of the detection region based on the information stored in thememory.
 21. The sensor according to claim 20, wherein: when theprocessor executes the instructions stored in the memory, the processorcauses the integrated circuit to: acquire first coordinates of thestylus in a diagonal coordinate system including the first and seconddirections when the integrated circuit determines that the firstintersection is positioned on the edge portion of the detection region,acquire second coordinates indicating a relative position of the styluswith respect to the first intersection in the diagonal coordinatesystem, map third coordinates of the first intersection in the diagonalcoordinate system on fourth coordinates in a normal coordinate systemincluding the long-side direction and a short-side direction of thefirst substrate, map the second coordinates on fifth coordinatesindicating a relative position of the stylus with respect to the firstintersection in the normal coordinate system, and acquire sixthcoordinates of the stylus in the normal coordinate system based on thefourth coordinates and the fifth coordinates.